Allow splitting in clauses in C-style for loop.

lib/src/source_visitor.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart_style.src.source_visitor;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/source.dart';
 
@@ skipping 469 matching lines @@
   }
 
   visitEmptyFunctionBody(EmptyFunctionBody node) {
     token(node.semicolon);
   }
 
   visitEmptyStatement(EmptyStatement node) {
     token(node.semicolon);
   }
 
+  visitEnumConstantDeclaration(EnumConstantDeclaration node) {
+    throw new UnimplementedError("Enum formatting is not implemented yet.");
+  }
+
+  visitEnumDeclaration(EnumDeclaration node) {
+    throw new UnimplementedError("Enum formatting is not implemented yet.");
+  }
+
   visitExportDirective(ExportDirective node) {
     visitDeclarationMetadata(node.metadata);
     token(node.keyword);
     space();
     visit(node.uri);
     _visitCombinators(node.combinators);
     token(node.semicolon);
   }
 
   visitExpressionFunctionBody(ExpressionFunctionBody node) {
@@ skipping 54 matching lines @@
     }
     space();
     token(node.inKeyword);
     space();
     visit(node.iterator);
     token(node.rightParenthesis);
     space();
     visit(node.body);
   }
 
-  visitEnumConstantDeclaration(EnumConstantDeclaration node) {
-    throw new UnimplementedError("Enum formatting is not implemented yet.");
-  }
-
-  visitEnumDeclaration(EnumDeclaration node) {
-    throw new UnimplementedError("Enum formatting is not implemented yet.");
-  }
-
   visitFormalParameterList(FormalParameterList node) {
     token(node.leftParenthesis);
 
     // Allow splitting after the "(" but not for lambdas.
     // TODO(rnystrom): Need to check for comments in empty parameter list.
     // See visitArgumentList.
     if (node.parameters.isNotEmpty && !_isLambda(node)) zeroSplit();
 
     // Try to keep the parameters together.
     _writer.startSpan();
@@ skipping 21 matching lines @@
     token(node.rightDelimiter);
 
     token(node.rightParenthesis);
     _writer.endSpan();
   }
 
   visitForStatement(ForStatement node) {
     token(node.forKeyword);
     space();
     token(node.leftParenthesis);
+
+    _writer.startMultisplit();
+
+    // The initialization clause.
     if (node.initialization != null) {
       visit(node.initialization);
     } else {
       if (node.variables == null) {
         space();
       } else {
-        visit(node.variables);
+        // Indent split variables more so they aren't at the same level
+        // as the rest of the loop clauses.
+        _writer.indent(2);
+
+        var declaration = node.variables;
+        visitDeclarationMetadata(declaration.metadata);
+        modifier(declaration.keyword);
+        visitNode(declaration.type, after: space);
+
+        visitCommaSeparatedNodes(declaration.variables, between: () {
+          _writer.multisplit(space: true, nest: true);
+        });
+
+        _writer.unindent(2);
       }
     }
+
     token(node.leftSeparator);
-    space();
+    _writer.multisplit(nest: true, space: true);
+
+    // The condition clause.
     visit(node.condition);
     token(node.rightSeparator);
+
+    // The update clause.
     if (node.updaters != null) {
-      space();
-      visitCommaSeparatedNodes(node.updaters);
+      _writer.multisplit(nest: true, space: true);
+      visitCommaSeparatedNodes(node.updaters,
+          between: () => _writer.multisplit(nest: true, space: true));
     }
+
     token(node.rightParenthesis);
-    if (node.body is! EmptyStatement) {
-      space();
-    }
+    _writer.endMultisplit();
+
+    // The body.
+    if (node.body is! EmptyStatement) space();
     visit(node.body);
   }
 
   visitFunctionDeclaration(FunctionDeclaration node) {
     visitMemberMetadata(node.metadata);
     modifier(node.externalKeyword);
     visitNode(node.returnType, after: space);
     modifier(node.propertyKeyword);
     visit(node.name);
     visit(node.functionExpression);
@@ skipping 891 matching lines @@
   /// Gets the 1-based line number that the beginning of [token] lies on.
   int _startLine(Token token) => _lineInfo.getLocation(token.offset).lineNumber;
 
   /// Gets the 1-based line number that the end of [token] lies on.
   int _endLine(Token token) => _lineInfo.getLocation(token.end).lineNumber;
 
   /// Gets the 1-based column number that the beginning of [token] lies on.
   int _startColumn(Token token) =>
       _lineInfo.getLocation(token.offset).columnNumber;
 }